Shotshell wad

ABSTRACT

A two part wad column for use in shotshells is provided which consists of an overpowder component comprising inner and outer concentric cylindrical walls attached to a skirted and plate and a shot container component comprising a cup-shaped shot container and a skirted end plate which abutts the outer cylindrical wall of the overpowder component.

United States Patent McCaffrey et al. [4 June 20, 1972 [54] SHOTSHELL WAD 72 inventors: Francis Hamnet Garland McCaffrey, [56] Refmnc Brownsburg, Quebec; Jack Garnett Mcln- U D ST PATENTS doe; Herbert Rigg, both of Lachute, Quebec, a" f Canada 3,289,586 12/1966 Horn el al. 102/42 C 3,405,638 10/1968 Stoner. .lr 102/42 C [73] Assignee: Canadian Industries Limited, Montreal,

Quebec, Canada Primary E.raml'nerRobert F. Stuhl 221 Filed: April 19, 1971 [21] Appl. No.: 135,095 [57] ABSTRACT A two part wad column for use in shotshells is provided which [30] Foreign A li ation Priority Data consists of an overpowder component comprising inner and outer concentric cylindrical walls attached to a skirted and June 10,1970 Canada ..085160 plate and a shm container onent comprising a cupshaped shot container and a skirted end plate which abutts the outer cylindrical wall of the overpowder component. [58] Field of Search 102/42, 42 C, 95 4 Claims, 6 Drawing Figures P'A'TiN'TEflJunzo I972 3. 670.650

INVENTORS Francis Hamner Garland McCAFFREY Jack Gornefl MclNDOE Herbert RIGG ATENT AGENT SHOTSIIELL WAD The present invention relates to a wad column for use in shotshells and in particular to a wad column which results in improved ballistic characteristics.

By wad column is meant the cushioning means or midwad which is interposed between the propellant charge and the shot within a shotshell casing together with a cooperating shot-containing pouch or shot concentrator. The function of the mid-wad component is to transmit the pressure of the expanding gases from the ignitied propellant to the shot charge contained-in the shot container in such a way that maximum propulsion of the shot is obtained with minimum recoil effect to the shooter and without the undesirable result of shot stringing" or scattering" caused by excessive distortion of individual pellets in the shot charge when the cushioning effect of the wad is not adequate.

One object of the present invention is to provide a novel wad column which will improve the ballistic and other properties of shotshell cartridges.

Another object is to provide awad column which is light in weight, economic to manufacture and which may be conveniently loaded into shotshells by automatic loading machinery.

Other objects will appear hereinafter.

The improved shotshell wad column of the invention comprises (a) a mide-wad having an outer flexible cylindrical wall and a spaced-apart inner concentric cylindrical wall of a length equal to or less than the length of said outer wall, an integral lower end plate at right angles to said inner and outer cylindrical walls, said end plate having an integral downwardly disposed tapered circumferential skirt, the said inner and outer cylindrical walls being tapered upwardly from their point of attachment to the said end plate, the said outer cylindrical wall being of a diameter less than the diameter of the said plate and said outer cylindrical wall having at least three longitudinal integral ribs thereon, the said ribs together with said outer cylindrical wall being of a diameter equal to or larger than the diameter of the said end plate, the whole of the said wad being adapted for telescopic reception in a shotshell cartridge case; and (b) a cup-shaped shot container having a cylindrical side wall and an integral lower end plate, said end plate having an integral downwardly disposed circumferential skirt, the said shot container being butted against the leading edge of the outer cylindrical wall of the said mid-wad, in such a way that the said outer cylindrical wall of the said mid-wad contacts an internal surface of the said downward skirt of said shot container.

The wad of the invention may be more fully understood by reference to the following drawing wherein:

F IG. 1 is a side view partly in section of a shotshell cartridge containing the wad column of the invention;

FIG. 2 shows a perspective view of the mid-wad of FIG. 1;

FIG. 3 shows a plan view of the mid-wad of FIG. 2;

FIG. 4 shows in cross section one type of shot container suitable for use with the wad of the invention;

FIG. 5 shows a perspective view of the base end of one embodiment of a shot container suitable for use in the wad column of the invention; and

FIG. 6 shows a cross section taken along the line A-A of FIG. 4.

Referring to FIG. 1 there is shown a conventional shotshell l which may be of paper or plastic containing a propellant charge 2 and a shot charge 3. Shot charge 3 is contained in shot container 4 having a gas-sealing skirt 4a. Molded plastic overpowder mid-wad 5 is interposed between propellant charge 2 and shot container 4. Wad 5 comprises an outer tapered cylindrical wall 6 and a concentric inner tapered cylindrical wall 7 integral with end plate 8. End plate 8 has a downwardly disposed tapered, circumferential gas-sealing skirt 9. As shown, inner cylindrical container 4 rests so that an inner surface of skirt 4a is on the upper rim of outer wall 6.

Referring to FIG. 2 the overpowder mid-wad is shown in perspective. Shown are outer tapered cylindrical wall 6 and concentric inner tapered cylindrical wall 7 both integrally formed with end plate 8. The outer surface of outer wall 6 has integrally formed thereon ribs 10 and 11. At least 3 and preferably 4 such ribs are required to assist in maintaining the wad in a centered location within a shotshell and to minimize surface contact between the wad and the shotshell casing.

In FIG. 3, which depicts a downward view into mid-wad 5, there is shown the inner and outer concentric cylindrical walls 7 and 6 and integral end plate 8. Also shown are integrally formed ribs 10 and 11 on the outer surface of wall 6. Ribs l0 and 11 extend outward from wall 6 only to the diameter of end plate 8.

In FIGS. 4 and 6 there is shown a shot container 12 particularly useful to handloaders when employing the wad of the invention. The container 12 has at its base 13 a downwardly directed thin-wall tubular structure 14 with internal ribs 14A integral with base 13. Tubular structure 14 may be inserted into or over, but preferably over, cylindrical wall 7 of wad 5 to aid in the assembly of a hand loaded shotshell. This makes a one piece assembly which is easier to insert into the shell when using hand loading equipment.

In FIG. 5 there is shown a shot container 15 which is particularly suitable for use with the wad column of the invention. In the embodiment shown, which is viewed from the base end, the gas-sealing skirt 16 comprises an extension of cylindrical wall 17 beyond end plate 18. Inward sloping, integral buttress ribs 19 are located at the junction of skirt l6 and end plate 18 and in an assembled shotshell are adapted to cause the abutting outer wall 6 of mid-wad 5 to turn inward upon contact therewith.

In the manufacture of a shotshell containing the overpowder wad of the invention, with reference to the figures of the drawing, the shotshell cartridge 1 containing the powder charge 2 is further assembled by inserting therein mid-wad 5. Mid-wad 5 is inserted with end plate 8 and gas-sealing skirt 9 adjacent to the powder charge 2. Integral ribs, such as 10 and 11 help maintain wad 5 centrally in cartridge 1. Mid-wad 5 may be made in a series of lengths for use with various combinations of powder and shot charges and the wad chosen will depend on the space available within the shotshell. The shot charge 3, contained in shot container 4, is loaded into the shotshell so that an inner surface of skirt 4a rests on the leading edges of cylindrical wall 6. It is generally recognized that the use of a shot container or pouch improves the density of shot pattern when the shotshell is discharged. After insertion of the shot charge, the mouth of the shotshell is closed in a conventional manner.

In the firing of the shotshell of FIG. 1, gases generated by the ignition of powder charge 2 are sealed by means of skirt 9 and propel wad 5 forward against the inertia of shot charge 3. As wad 5 moves forward, the tapered ends of wall 6 turn inward, guided by the skirted or buttressed base end of shot container 4, and collapse inward towards end plate 8. At the same time, outward pressure is exerted against skirt 4a forcing it outward against the walls of shotshell l to form a secondary seal against any gases which may have passed mid-wad 5. As the forward movement of wad S continues, wall 7 contacts the base of shot container 4 and in turn collapses towards end plate 8. The sequential collapse of walls 6 and 7 provide a unique and cooperative effect in cushioning the impact caused by the expulsion of the shot charge by the expanding gases. This cushioning has been found to provide ballistic properties which are superior to those found in shotshells of the prior art.

The material of construction of the wad of the invention is preferably low priced, low density polyethylene of a density of about 0.920 gms/ml. although other thermoplastics such as, for example, polypropylene and mixtures of polyethylene and polypropylene may be employed. Because of the relatively thin sections of the wad of the invention, particular economies may be enjoyed by virtue of rapid molding times and a maximum number of cycles per minute which are possible during fabrication. Because of the design of both the shot container and the mid-wad of the wad column of the invention, relatively simple molding equipment may be used in their fabrication. Unlike the one piece wad columns of the prior art which requires large expensive multiple-cavity, slow acting molds, the present components may be made quickly and efficiently.

the invention provided high velocity and low pressure together with a superior shot pattern. It can also be seen from the results obtained that if the weight of propellant charge was selected to produce the same velocity in all samples, more Additionally, the small bulk and light weight of the wad 5 propellant would be required in all cases except Manufacturer reduces the recoil experienced by the shooter. This small bulk D and in all cases the pressure would be higher than with the and light weight is due in large measure to double gas-sealing wad of the present invention. With reference to the recoil" provided by the wad column, which function permits a u results, it can be seen that in all cases recoil was greater in the stantial reduction in the mass of the wad column components. competitive samples. The effect of such recoil could be over- The wad of the present invention assembled in a Shot-Shell come by employing a heavier gun when using the competitive as Sh n in H 1 was tested g in h r om e ci y shotshells but this is generally undesirable for the sportsman available shotshells and columns. The results of these tests are r hu ter. given in the Example and Table shown below.

EXAMPLE 1 5 What we claim is: I

l. A shotshell wad column comprising:

A series of loaded shotshells containing the wad column of a, a resilient thermoplastic overpowder i h i an the invention as well as a series of loaded shotshell using wad outer cylindrical wall d a spaeed apan inner Concentric columns found in well known and commercially available eyhndrieal n fa length equal to or l h the length Shot-Shells were P p for comparison Purposes as followsof said outer wall, an integral lower end plate at right an- Ohe hundred Primed, P y- Plastic 12 gauge shotshells were gles to said inner and outer cylindrical walls, said end hand charged with grains of POpellam of the yp plate having an integral downwardly disposed, tapered y used in field load shotshells At random 20 of hese circumferential skirt, the said inner and outer cylindrical were selected to be used with the wad column of the present walls being tapered upwardly f their point f invention as Show" in 1 of the drawing and groups of 20 tachment to said end plate, the said outer cylindrical wall others were each assembled using wad components found in being of a diameter less than the diameter of said integral the shotshells of manufacturers r C and After Seating end plate and said outer cylindrical wall having at least the wad columns to a common pressure, 282 hand counted three longitudinal integral rihe thereon, the Said rihs No.6 hard shot pellets were charged into each shell. The together with the Said outer cylindrical n being f a loaded shells were crimped closed with a folded crimp and 10 diameter equal to the diameter f Said end plate, the shotshells of each lot were mixed together in a container and whole f the Said wad being adapted f telescopic recap. selected at random for test firing. At test firing the following tion in a shot sheu cartridge case; and characteristics were checked.

a. The velocity of the shot over a distance of three feet at a distance of three feet from the muzzle. b. a resilient thermoplastic cup-shaped shot container havb. The pressure generated within the shotshell. ing a cylindrical side wall and an integral lower end plate,

c. The shot pattern of the shot pellets. said end plate having an integral downwardly disposed The velocity of shot was determined electronically and circumferential skirt, the said shot container being butted recorded in feet/second. The pressure was measured by means against the leading edge of the outer cylindrical wall of of the standard lead crusher test used in the industry and the said mid-wad in such a way that the said outer cylinrecorded in lead units of pressure (l.u.p.). The pattern was drical wall of the said mid-wad contacts an internal surdetermined by counting the number of shot pellets falling face of the said downwardly disposed skirt of said shot within a 30 inch diameter circle at a distance of 40 yards from container. the muzzle. Pattern results were expressed as a percentage of the pellets falling within the target circle.

In addition, the remaining 10 loaded ShOtSilBii in each i0! 2, A wad column as laimed in claim 1 wherein the circumwere fired randomly in a recoil testing Field Proof Gun. in this f mi l kin f h id h d h container h i test, the pound test gun is suspended by cr S ir WhiCh tegrally attached thereto inward sloping, spaced apart buttress permit the gun to move horizontally rearwa d in recoil a e ribs, said ribs also being integral with the underside of the said time of firing. This rearward movement is recorded on a slidd l e, ing scale. Such measured recoil may then be converted to mo- 50 mentum and expressed as such.

From the test data it is possible to show an average velocity 3. A wad column as claimed in claim 1 wherein the said cupfor each 100 units of pressure. Such a comparison indicates shaped shot container has a central, downwardly disposed the efficiency of a wad column system where the combination cylindrical wall integral with the said end plate, the said of low pressure and high velocity indicates a more efficient use downwardly disposed cylindrical wall being adapted to teleof propellant by virtue of a more effective wad column. scopically engage the said inner cylindrical wall of the said The results of the tests are shown in the Table below. overpowder mid-wad.

TABLE Velocity per 100 Pattern, percent Wad weight units of shot in 30 in. Recoil Shotsliell sample (grams) Velocity (it./sec.) Pressure (l.u.p.) pressure circle at 40 yds. (inches) Momentum Present invention 1. 1.932 1,294-(1,268l,311) 10,240-(9, 300-10, 500) 12.64 82.2-(76.689.4) 10.59 112. 5 Manufacturer 2. 820 1, 248-(1,2231,272) 10, 640-00, 200-10, 800) ll. 73 6.2(72.780. 8) 10.76 114.3 Manufacturer B... 2, 097 1, 274-(1,253-1, 292) 10, 220-(10, 000-10, 700) 12. 47 80. 1-(76. 9-83.13) 10. 113.1 Manufacturer C... 2. 323 1, 280-(1, 267-1, 288) 10,810(10, 200-11, 200) 11. 84 79. 4-(69. s-ssa) 10.75 114. 2 Manufacturer D 2. 700 1, 204-(1.2821,306) 11, 530-(11.300-11,s00) 11. 22 78. 4-(75. 581.9) 10.97 116. 5

4. A wad column as claimed in claim I wherein the resilient thermoplastic is polyethylene of a density of about 0.92 gram per ml.

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1. A shotshell wad column comprising: a. a resilient thermoplastic overpowder mid-wad having an outer cylindrical wall and a spaced-apart inner concentric cylindrical wall of a length equal to or less than the length of said outer wall, an integral lower end plate at right angles to said inner and outer cylindrical walls, said end plate having an integral downwardly disposed, tapered circumferential skirt, the said inner and outer cylindrical walls being tapered upwardly from their point of attachment to said end plate, the said outer cylindrical wall being of a diameter less than the diameter of said integral end plate and said outer cylindrical wall having at least three longitudinal integral ribs thereon, the said ribs together with the said outer cylindrical wall being of a diameter equal to the diameter of said end plate, the whole of the said wad being adapted for telescopic reception in a shot-shell cartridge case; and b. a resilient thermoplastic cup-shaped shot container having a cylindrical side wall and an integral lower end plate, said end plate having an integral downwardly disposed circumferential skirt, the said shot container being butted against the leading edge of the outer cylindrical wall of the said mid-wad in such a way that the said outer cylindrical wall of the said mid-wad contacts an internal surface of the said downwardly disposed skirt of said shot container.
 2. A wad column as claimed in claim 1 wherein the circumferential skirt of the said cup-shaped shot container has integrally attached thereto inward sloping, spaced apart buttress ribs, said ribs also being integral with the underside of the said end plate.
 3. A wad column as claimed in claim 1 wherein the said cup-shaped shot container has a central, downwardly disposed cylindrical wall integral with the said end plate, the said downwardly disposed cylindrical wall being adapted to telescopically engage the said inner cylindrical wall of the said overpowder mid-wad.
 4. A wad column as claimed in claim 1 wherein the resilient thermoplastic is polyethylene of a density of about 0.92 gram per ml. 